A gametangium (plural: gametangia) is an
organ or
cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
in which
gametes are produced that is found in many multicellular
protist
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclu ...
s,
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthesis, photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from u ...
,
fungi, and the
gametophytes of
plants. In contrast to
gametogenesis in
animal
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
s, a gametangium is a
haploid structure and formation of gametes does not involve
meiosis.
Types of gametangia
Depending on the type of gamete produced in a gametangium, several types can be distinguished.
Female
Female gametangia are most commonly called
archegonia. They produce
egg cell
The egg cell, or ovum (plural ova), is the female reproductive cell, or gamete, in most anisogamous organisms (organisms that reproduce sexually with a larger, female gamete and a smaller, male one). The term is used when the female gamete is ...
s and are the sites for
fertilization
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...
. Archegonia are common in algae and primitive plants as well as
gymnosperms. In
flowering plants, they are replaced by the
embryo sac
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fem ...
inside the
ovule.
Male
The male gametangia are most commonly called
antheridia
An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. Androecium is also t ...
. They produce
sperm cells
A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, ...
that they release for fertilization. Antheridia producing non-motile sperm (spermatia) are called spermatangia. Some antheridia do not release their sperm. For example, the
oomycete
Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the resul ...
antheridium is a
syncytium with many sperm
nuclei and fertilization occurs via fertilization tubes growing from the antheridium and making contact with the egg cells. Antheridia are common in the gametophytes in "lower" plants such as
bryophyte
The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in s ...
s,
ferns,
cycad
Cycads are seed plants that typically have a stout and woody ( ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or ...
s and
ginkgo. In "higher" plants such as
conifers and flowering plants, they are replaced by
pollen grain
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametoph ...
s.
Isogamous
In
isogamy
Isogamy is a form of sexual reproduction that involves gametes of the same morphology (indistinguishable in shape and size), found in most unicellular eukaryotes. Because both gametes look alike, they generally cannot be classified as male or f ...
, the gametes look alike and cannot be classified into "male" or "female." For example, in
zygomycete
Zygomycota, or zygote fungi, is a former division or phylum of the kingdom Fungi. The members are now part of two phyla: the Mucoromycota and Zoopagomycota. Approximately 1060 species are known. They are mostly terrestrial in habitat, living i ...
s, two gametangia (single
multinucleate cells at the end of
hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
e) form good contact with each other and fuse into a zygosporangium. Inside the zygosporangium, the nuclei from each of the original two gametangia pair up.{{clarification needed, reason=to what end?, date=July 2021
See also
*
Zoosporangium
A zoospore is a motile asexual spore that uses a flagellum for locomotion. Also called a swarm spore, these spores are created by some protists, bacteria, and fungi to propagate themselves.
Diversity Flagella types
Zoospores may possess one or mo ...
, a gametangium that produces motile isogamous gametes, called
zoospores
Reproduction
Reproductive system
Germ cells